UPDATED: 12/4/2012 – 10:02 p.m.

CHICAGO (CBS) — A teachers’ strike in the state’s sixth largest school district has ended, after Community Unit School District 300 in the northwest suburbs reached a tentative contract agreement with its 1,300 union teachers.

The district covers more than 20,000 students at schools in Algonquin, Lake in the Hills, Carpentersville and West Dundee.

Tuesday night, the two sides announced they had reached a tentative three-year deal, and classes would resume on Wednesday.

“We did not have a mediator with us today. I think that was a benefit to us; to be able to have face-to-face meetings, and to be able to sit down and have those heart-to-heart discussions – what are our priorities on both sides, and to say ‘Okay, how do we get there?’” said District 300 board president Anne Miller.

LEAD 300 spokesman Mike Williamson said, “I think we’ve come to a place where we can actually start building the future that we’re looking for for District 300.”

Details of the tentative deal were not immediately available, but teachers and the district had been at odds over pay and class size.

About 1,300 teachers represented by Local Education Association of District 300 had gone on strike Tuesday morning after declaring an impasse in contract talks, but negotiations resumed at 3 p.m. Tuesday, and the deal was announced shortly before 9 p.m.

CBS 2’s Marissa Bailey reports Tuesday morning’s strike left many parents scrambling to find daycare as teachers walked the picket line.

Many students joined their teachers on the picket line Tuesday, with students in homemade “We Are 300” T-shirts, and teachers in “We Lead 300” shirts. All were hoping the show of solidarity sends a message to negotiators.

Dundee Heights High School senior Tyler Jones said, “They teach you life lessons that you need, and I could never thank them enough for that. So being out here and showing my support is the closest thing I could do.”

Support is the reason one 5th grade teacher was limping along the picket line Tuesday, just five weeks after getting pins in her foot.

“I think all teachers are seriously dedicated, because what they do, they do for their students,” Dawn Pociask said.

A painted red line in the grass set the strike picket boundary, quite literally, outside the high school. Union spokesman Mike Williamson said the spray paint appeared like an intimidation tactic on the part of the school board.

Teachers and the district seemed to have reached an agreement on salary by Tuesday afternoon, and the impasse appeared largely due to a dispute over class sizes, with teachers wanting more one-on-one time with students.

“It’s hard to do that when you got … 34 kids sitting in a room that’s made for 25,” music teacher Randall Valdivia said.

While support for the teachers was evident, there’s no doubt the strike was posing problems for parents.

“My kids go to school maybe 10, 15 minutes away, so I have to drive all the way up here, pick them up, and then go back home. So I hope they can work something out,” Celestine Wilson said.

The one charter school in District 300, Cambridge Lakes Charter School, in Pingree Grove, was not affected by the strike.

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